#include  using namespace std ; struct activity {

int id , start , end ;};

bool compare(activity a , activity b) { return a .end < b.end ;

}

int schedule (int n , activity * p) { sort(p , p + n , compare);

    int cnt = 0 , end = 0;

    for (int i = 0; i < n; i++) {

        if (p[i].start >= end) { end = p [i].end ;

            cnt++;

        }

    }

    return cnt;
}